Machine for molding helical gears



July 24, 1951 J. HALLER MACHINE FOR MOLDING HELICAL GERS Filed July 21,1949 2 Sheets-Sheet l I1 .Hmm/ A ilm A l w 4. QW W5@ 3 uw M W..

July 24, 1951 J. HALLER MACHINE FOR MoLnING HELICAL SEARS 2 Sheets-Sheot2 Filed July 2l, 1949 Patented July 24, 1951 OFFICE 2,561,735 1 MACHINEFon MoLDING HELICAL GEARs f John Hauer, Northviue, Miti..` ApplicationJuly 21, 1949, Serial No. 106,044

making gears.

One object of this invention is to provide a machine and process formaking helical gears and retracted out of the mold cavity.

Another object is to provide a machine and process for making helicalgears from powdered In the drawings:

Figure 1 is a fragmentary central vertical section, partly in sideelevation, of a molding machine for molding form of the invention, ingposition;

Figure 2 is a fragmentary side elevation, `partly in central verticalsection, of the molding vInachine shown in Figure l, advanced to itsmolding position;

Figure 3 is a horizontal section through the plunger rotating mechanism,taken along the line 3-3 in Figure 2;

Figure 4 is a vertical section taken along the line `4l-4 in Figure 3;

Figure 5 is a diagrammatic central vertical section through the centralportion of Figure `1, with the parts in the same position as jFigure 1,but with the mold cavity filled with powdered maten rial; i 1

Figure 6 is a view similar to Figure 5, but vwith the molding plungeradvanced to its position at the end of its molding stroke;

Figure 7 is a view similar Ato Figures-*5 and 16,

retracted from its moldhelical gears, according to one table or bed I3or :mold block I8 11 Claims. (Cl. `'fsm-5) but with the molding plungerretracted and the ejection plunger advanced to eject the moldedworkpiece; and i Figure 8 is a side elevation of the workpiece producedby the molding operations of Figures l5, V6 and 7, namely, a helicalgear.

`In general, the machine and present invention provide means and. amethod f Referring to the drawings generally, Figure l shows in centralvertical section the central por- *tionof a molding press, generallyvdesignated lll,

a mold or die, generally designated I6.

`Referring to t` e drawings in detail, the press is provided with'acountersunk bore Il in which a correspondingly flanged die issecured asby the screws I9. The mold block 1in turn contains a stepped andcountersunk bore 20 congured to receive the -end of the casing 42, sunkas at 65 for that purpose. The closure plate 'screws 1 9 (Figure 1)sponding parts are designated with the same reference numerals and asingle description will vsuiice for both. The rack bars are locked inposition by lock nuts 3| threaded upon the threaded portions 29 and attheir outer ends are provided with rack inserts 32 in the form ofelongated bars having rack teeth 33 on one face thereof, the oppositeface being secured in a recess 34 (Figure 4) in the enlarged portion 35of the rack bar '30 by screws 36 threaded therein. The enlarged portion35 of each rack bar 36 is of approximately rectangular cross-section(Fig--l ure 3) and is slidably received in a vertical slot or bore 31 ofcorresponding rectangular crosssection, the outer wall of the bore 31being formed by a retaining plate 38 bolted thereto as at 3 (Figure 1).i i The rack insert 32 projects inward through an opening 40 from thebore 31 into a horizontal bore-like cavity 4I (Figure 3) in the upperportion of the housing 42 of the plunger rotating device I4 or I5. Thecavity 4I is closed by an access plate 43 secured thereto as at 44.Mountedwithin the cavity 4| v and meshing with the teeth 33 of the rackinsert 32 is a pinion 45. The pinion 45 is mounted upon` the reduceddiameter end46 of a shaft 41 the end of which is threaded as at 48 toreceive a retaining nut 49 (Figure 3). The horizontal bore-like cavity4I has annular recesses 50 and 5| for receiving the outer races ofanti-friction bearings 52 and 53 in which the opposite ends of the shaft41 are journaled. Mounted on or integral with the shaft 41 is a worm 54.The opposite end of the shaft 41 from the end 48 is threaded as at 55 toreceive a retaining nut 56, and the outer end of the cavity y4I isclosed by an access plate 51 similar to the access plate 43 andsimilarly bolted as at 58 to the housing 42. The`casing42 itself isbored as at 59 (Figures 3 and 4) to receive bolts 60 which pass throughcorrespondingly aligned vertical bores 6I in the upper and lower platensII and I2 and by means of which the plunger rotating devices I4 and I5arev secured to their respective platens II and I2. The casing 42 isprovided with a vertical bore-like cavity 62 (Figures 1 and 3) openinginto the horizontal cavity 4I Vand closed by a closure plate 63 (Figurel)- bolted as at 64 to the upper the cavity 62 being counter- 63 andplatens II and I2 are provided with bores 66 and 61 coaxial with thecavity 62 for receiving a core rod or inner plunger 68 (Figure l) thisbeing used in the present set-up of the machine II) only with thelowerrplunger rotating device I5.

Y The bore-like cavity 62 is provided with an annular enlarged portion69 (Figure l) in which are mounted oppositely yfacing tapered rollerbearings 1|)v and 1 I separated by the spacing sleeve 12. Journaled inthe tapered roller bearings 10 and 1| is a tubular shaft 13 having abore 14 therethrough for the passage of the core rod or innerplunger 68.The tubular shaft 13 is threaded as at 15 to receive -a retaining nut16, the lower end of they tubular shaft 13 being provided with an'enlargement 11 which engages the inner race of the anti-friction bearing1 I, the retaining nut 16 engaging the corresponding inner race of theanti-friction bearing 10 to hold these parts in' assembly. The end ofthe vertical bore-like cavity 62' adjacent the enlargement 11 is closedby an access plate 18 secured thereto as by the The access plate 18 isbored asat for the passage of the enlargement 11 of the shaft '13. Keyedor otherwise drivingly secured as at 8| to the end of the shaft 13adjacent the threaded portion 15 is a worm gearfor worm Wheel 62 whichmeshes with and is driven by the worm 54, thereby rotating the tubularshaft or plunger 13.

A tapered roller thrust bearing 83 is interposed between the worm gear62 and the access plate 63 at the upper end of the casing 42 of theupper plunger rotating device I4. The tubular shaft 13 of the upperplunger rotating device I4 is provided with a counterbore or socket 84'for receiving the upper end of the upper molding plunger "85, thelatter being held in position by a retaining ring 86 secured to theshaft enlargement 11 as by the screws 81. The lower end of the plunger86 is provided with a bore 88 adapted to receive the core rod 68 (Figure6) and opening into an enlarged bore 89 (Figure 1) which in turn opensinto a bore 90 having a port 9| extending transversely therefrom to theatmosphere. The upper molding plunger is provided witha helical ridge 92of configuration corresponding to the tooth or teeth of the helical gearG (Figure 8) to be molded.

The llower tubular shaftv 13, on the other hand, is not provided withthe socket or counterbore 84 (Figure l) but carries the lower tubularplunger 93 in end-abutting engagement. A re taining ring 94 secured asby the. screws 95 to the shaft enlargement 84 on the lower shaft 13holds the lower tubular plunger 93 in assembly with the lower shaft 13.The lower tubular plunger 93 is provided with an axial bore 96 for thepassage of the core rod 68 and of approximately the same diameter plus asuitable clearance, so that the core rod 68 may slide axially relativelyto the plunger 93. The plunger 93 is also provided with a helical rib orribs 91 corresponding to the tooth or teeth of the gear G to be molded(Figure 8). Thus, the ridge or ridges 91 of the lower plunger 93 willcorrespond in conguration to the ridge or ridges 92 on the upper plunger85.

The die or mold I6 is provided with a borelike mold cavity 98 havinghelical grooves 99 corresponding in configuration to the helical ridges92 and 91 on the upper and lower plungers 85 and 93 (Figure l). The moldcavity 98 with its grooves 99 and helical ridges |00 between the grooves99 is thus the counterpart of the teeth I6I and roots |62 of the gear Gto be molded (Figure 8). The gear G may also be provided with an axialbore |03 for mounting it upon a shaft, in which case the core rod 68 isemployed for that purpose. If the gear G is solid, the

y lower plunger 93 is likewise solid and the core rody 68 may beomitted. A gear with too great a tooth angle relatively to the axis isnot selfstarting in its ejection from the mold cavity after molding,hence the teeth or helical ridges of the gear should preferably make anangle of 30 or less with the axis of the gear, in order to beselfstarting.

Operation operator now operates the mold charging apparatus, such asco-pending ap- 780,851 previously referred V is ll, the mold cavity 98with powdered material, such as powdered metal. Optionally, of course,the mold cavity 98 may be The parts now occupy the relative positionsshown in Figure 5.

The operator now advances the upper platen I I downward so that thehelically ridged plunger 85 will enter the mold cavity 9s and Compressthe charge of powdered material. As the upper platen I I moves downward,or the lower platen I2 moves upward, the pinion 45 rolls along the rackteeth 33` of the stationary rack shaft 30, 35, consequently rotatingrthe shaft 47, worm 54, worm gear or wheel 82 (Figure 3), hollow sha-ftpowdere powdered material comprising ol'powdered material. The operator`then recharges tl'iemold cavity 98 in the manner pre- Viouslydescribed, whereupon the molding opera- `tion is repeated as describedabove. The operation may `be carried out repeatedly ior the pronumber ofworkpieces, `according to the foregoing precedure.

" `What I claim is:

1. A 'machine for molding helical gears from wder d material comprisinga frame structure,

groove upon arrival mold.

2. A machine for powdered A machine for molding helical gears frommaterial comprising a frame structure,

-4. A machine for molding helical gears from a frame structure,

from said mold, lmounted on site ends, said cavity on opposite sides oisaidmold nism with said mechanism for advancing said plunger. carriertoward said mold, a rack connected to said frame structure, a pinionmeshing with said rack, and worm gearing drivingly connecting said.pinion to said plunger y chronism with said plunger carrier advancingmechanism, said plunger rotating mechanism .being arranged to effectentry of the end ofv said ridge into the end of said` groove uponarrival of said plunger at said mold.

5. A machine for molding powdered material comprising a irame structure.a mold having a mold cavity openat its opposite ends, said cavity havinga helical groove therethrough, a pair of plunger carriers disposed onopposite sides oi said mold and movable to and fro along said framestructure toward and away a rotatable molding plunger each carrier inalignment with said mold cavity, each molding plunger having thereon ahelical ridge of pitch and configuration corresponding to said helicalgroove,.rnechanism for advancing said plunger carriers toward said mold,and mechanism for rotating said plungers in synchronism with saidplunger carrierl advancing mechanism, said plunger rotating mechanismbeing arranged to eiiect entry of the ends of said ridges yinto theopposite ends of said groove upon arrival of. said plungers at theopposite sides of said mold. v V t l 6. A machine for molding helicalgears from powdered material comprising a framestructure, a mold havinga mold cavity open at its oppohaving a vhelical groove of plungercarriers vdisposed and movable to and fro along saidirame structuretowardand away from said mold, a rotatable molding therethrough, a pairplunger mounted on said4 carrier 1n alignment with 4said mold cavity,each molding plunger having thereon a helical ridge of pitchandconfiguration corresponding to said helical groove, mechanism foradvancing said plunger carriers toward said mold, andmechanismuincluding intermeshing gearing drivingly connected to lsaidplungers for rotating saidplungers in synchroplunger carrier advancingmechanism, said plunger rotating mechanism L,being arranged to eiiectentry of the ends offsaid ridges into the opposite ends of said grooveupon arrival of said plungers at the opposite sides of said mold.

7. A machine for molding helical gears .from powdered materialcomprising a frame structure, a mold having a mold cavity open at itsopposite ends, said cavity having a helical groove therethrough, a pairof plunger carriers disposed on opposite sides of said mold and movableto and fro along said frame structure toward and away from said mold, arotatable molding plunger mounted on said carrier in alignment with saidmold cavity, each molding plunger having thereon a helical ridge ofpitch and configuration corresponding to said helical groove,mechanisrnor advancing said plunger carriers toward` said mold, andmechanism including a pair of racks connected to said frame structureand gearing drivingly connecting each rack to one of said plungers forrotating said plungers in synchronism with said plunger carrieradvancing mechfor rotating said plunger .Syn-

helical gears from anism, said plunger rotating mechanism being arrangedto effect entry of the ends of said ridges into the opposite ends oisaid groove upon arrival of said plungers at the opposite sides of saidmold.

8. A machine for molding helical gears from powdered material comprisinga frame structure, a mold having a mold cavity open at its oppositeends, said cavity having a helical groove therethrough, a pair ofplunger carriers disposed on opposite sides of said mold and movable toand fro along said frame structure toward and away from said mold, arotatable molding plunger mounted on said carrier in alignment with saidmold cavity, each molding plunger having thereon a helical ridge oipitch and configuration corresponding to said helical groove, mechanismfor advancing said plunger carriers toward said mold, a pair of racksconnected to said frame structure, a pinion meshing with each rack, andworm gearing drivingly connecting each pinion with its respectiveplunger for rotating said plunger in synchronism with said plungercarrier advancing mechanism, said plunger rotating mechanism beingarranged to effect entry of the ends of said ridges into the oppositeends of said groove upon arrival of said plungers at the opposite sidesof said mold.

9. A rotary molding plunger unit for a molding press having areciprocable platen comprising a housing attachable to said platen fortravel therewith, a molding. plunger rotatably mounted in said housing,a rack stationarily attachable to a stationary part of the press, apinion rotatably mounted in said housing and meshing with said rack, andgearing drivingly and rotatably connecting said plunger a molding presshaving a reciprocable platen comprising a housing attachable to saidplaten for travel therewith, a molding plunger rotatably mounted in saidhousing, a rack stationarily attachable to a stationary part of thepress, a pinion rotatably mounted in said housing and meshing with saidrack, and gearing drivingly and rotatably connecting said plunger tosaid pinion, said plunger having a helical ridge thereon.

11. A rotary molding plunger unit for a molding press having areciprocable platen comprising a housing attachable to said platen fortravel therewith, a molding plunger rotatably mounted in said housing.,a rack stationarily attachable to a stationary part of the press, apinion rotatably V housing and meshing with said rack, and gearingincluding an intermeshing worm and wormv wheel drivingly and rotatablyconnecting said plunger to said pinion.

JOI-1N HALLER.

REFERENCES CITED The following references are of record. in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,443,349 Cooke Jan. 30, 19232,253,003 Whipple Aug. 19, 1941 2,404,631 Gronemeyer July 26, 19462,447,434 Schwarzkopf Aug. 17, 1948

